Elevated Mitral Valve Pressure Gradient After MitraClip Implantation Deteriorates Long-Term Outcome in Patients With Severe Mitral Regurgitation and Severe Heart Failure

Impact of Intraprocedural Mitral Regurgitation and Gradient Following Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation

BACKGROUND

The impact of intraprocedural results following transcatheter edge-to-edge repair (TEER) in primary mitral regurgitation (MR) is controversial.

OBJECTIVES

This study sought to investigate the prognostic impact of intraprocedural residual mitral regurgitation (rMR) and mean mitral valve gradient (MPG) in patients with primary MR undergoing TEER.

METHODS

The PRIME-MR (Outcomes of Patients Treated With Mitral Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation) registry included consecutive patients with primary MR undergoing TEER from 2008 to 2022 at 27 international sites. Clinical outcomes were assessed according to intraprocedural rMR and mean MPG. Patients were categorized according to rMR (optimal result: ≤1+, suboptimal result: ≥2+) and MPG (low gradient: ≤5 mm Hg, high gradient: > 5 mm Hg). The prognostic impact of rMR and MPG was evaluated in a Cox regression analysis. The primary endpoint was 2-year all-cause mortality or heart failure hospitalization.

RESULTS

Intraprocedural rMR and mean MPG were available in 1,509 patients (median age = 82 years [Q1-Q3: 76.0-86.0 years], 55.1% male). Kaplan-Meier analysis according to rMR severity showed significant differences for the primary endpoint between rMR ≤1+ (29.1%), 2+ (41.7%), and ≥3+ (58.0%; P < 0.001), whereas there was no difference between patients with a low (32.4%) and high gradient (42.1%; P = 0.12). An optimal result/low gradient was achieved in most patients (n = 1,039). The worst outcomes were observed in patients with a suboptimal result/high gradient. After adjustment, rMR ≥2+ was independently linked to the primary endpoint (HR: 1.87; 95% CI: 1.32-2.65; P < 0.001), whereas MPG >5 mm Hg was not (HR: 0.78; 95% CI: 0.47-1.31; P = 0.35).

CONCLUSIONS

Intraprocedural rMR but not MPG independently predicted clinical outcomes following TEER for primary MR. When performing TEER in primary MR, optimal MR reduction seems to outweigh the impact of high transvalvular gradients.

Mitral regurgitation is associated with similar loss of von Willebrand factor large multimers but lower frequency of anemia compared with aortic stenosis

Background

Various cardiovascular diseases cause acquired von Willebrand syndrome (AVWS), which is characterized by a decrease in high-molecular-weight (large) von Willebrand factor (VWF) multimers. Mitral regurgitation (MR) has been reported as a cause of AVWS. However, much remains unclear about AVWS associated with MR.

Objectives

To evaluate VWF multimers in MR patients and examine their impact on clinical characteristics.

Methods

Moderate or severe MR patients (n = 84) were enrolled. VWF parameters such as the VWF large multimer index (VWF-LMI), a quantitative value that represents the amount of VWF large multimers, and clinical data were prospectively analyzed.

Results

At baseline, the mean hemoglobin level was 12.9 ± 1.9 g/dL and 58 patients (69.0%) showed loss of VWF large multimers defined as VWF-LMI < 80%. VWF-LMI in patients with degenerative MR was lower than in those with functional MR. VWF-LMI appeared to be restored the day after mitral valve intervention, and the improvement was maintained 1 month after the intervention. Seven patients (8.3%) had a history of bleeding, 6 (7.1%) of whom had gastrointestinal bleeding. Gastrointestinal endoscopy was performed in 23 patients (27.4%) to investigate overt gastrointestinal bleeding, anemia, etc. Angiodysplasia was detected in 2 of the 23 patients (8.7%).

Conclusion

Moderate or severe MR is frequently associated with loss of VWF large multimers, and degenerative MR may cause more severe loss compared with functional MR. Mitral valve intervention corrects the loss of VWF large multimers. Gastrointestinal bleeding may be relatively less frequent and hemoglobin level remains stable in MR patients.

Comparison of Transcatheter Edge-to-Edge Mitral Valve Repair for Primary Mitral Regurgitation Outcomes to Hospital Volumes of Surgical Mitral Valve Repair

BACKGROUND

Transcatheter edge-to-edge mitral valve (MV) repair (TEER) is an effective treatment for patients with primary mitral regurgitation at prohibitive risk for surgical MV repair (MVr). High-volume MVr centers and high-volume TEER centers have better outcomes than low-volume centers, respectively. However, whether MVr volume predicts TEER outcomes remains unknown. We hypothesized that high-volume MV surgical centers would have superior risk-adjusted outcomes for TEER than low-volume centers.

METHODS

We combined data from the American College of Cardiology/Society of Thoracic Surgeons Transcatheter Valve Therapy registry and the Society of Thoracic Surgeons adult cardiac surgery database. MVr was defined as leaflet resection or artificial chords with or without annuloplasty and was evaluated as a continuous variable and as predefined categories (<25, 25-49, and ≥50 MV repairs/year). A generalized linear mixed model was used to evaluate risk-adjusted in-hospital/30-day mortality, 30-day heart failure readmission, and TEER success (mitral regurgitation ≤2+ and gradient <5 mm Hg).

RESULTS

The study comprised 41 834 patients from 500 sites of which 332 (66.4%) were low, 102 (20.4%) intermediate, and 66 (13.2%) high-volume surgical centers (P<0.001). TEER success was 54.6% and was not statistically significantly different across MV surgical site volumes (P=0.4271). TEER mortality at 30 days was 3.5% with no significant difference across MVr volume on unadjusted (P=0.141) or adjusted (P=0.071) analysis of volume as a continuous variable. One-year mortality was 15.0% and was lower for higher MVr volume centers when adjusted for clinical and demographic variables (P=0.027). Heart failure readmission at 1 year was 9.4% and was statistically significantly lower in high-volume centers on both unadjusted (P=0.017) or adjusted (P=0.015) analysis.

CONCLUSIONS

TEER can be safely performed in centers with low volumes of MV repair. However, 1-year mortality and heart failure readmission are superior at centers with higher MVr volume.

Mitral valve gradient changes associate with outcomes of patients undergoing transcatheter edge-to-edge repair

INTRODUCTION

Transcatheter edge-to-edge repair (TEER) is typically used to treat mitral regurgitation (MR) in patients with high surgical risk. Increased post-procedural mitral valve gradient (MVG) may impact mortality and hospitalizations. We aim to evaluate and compare the absolute postprocedural MVG and the change in the MVG effect on outcomes for patients undergoing TEER therapy.

METHODS

Patients who underwent TEER for severe MR were divided into two groups, initially by postprocedural absolute MVG, TTE-based at discharge, and then by the difference between preprocedural and postprocedural MVG. Primary endpoints included all-cause mortality and heart failure hospitalization (HFH) during one year after the procedure.

RESULTS

The study included 100 patients. The mean MVG increased from 3.39 mmHg immediately after the procedure to 4.83 mmHg the following day, an increase of 1.44 mmHg (p < 0.001). First stratification was by MVG on the day following the procedure - MVG ≤5 mmHg (n = 70) and MVG >5 mmHg (n = 30). There was no significant difference in rates of survival (88.6%, 93.3%, p = 0.716) or HFH (18.6%, 33.3%, p = 0.178). Second stratification was by the difference in preprocedural and postprocedural MVG- delta MVG <3 mmHg (n = 55) and delta MVG ≥3 mmHg (n = 45). While survival rates did not significantly differ (87.3% vs. 93.3%, p = 0.503), delta MVG ≥3 mmHg correlated with higher HFH rates (12.7% vs. 35.6%, p = 0.014).

CONCLUSIONS

The MVG of patients undergoing TEER usually increases on the day after the procedure compared to the immediate post-procedure MVG. Higher delta MVG is associated with higher HFH rate.

Echocardiographic Profiling Predicts Clinical Outcomes After Mitral Transcatheter Edge-to-Edge Repair

BACKGROUND

Prior studies investigating the impact of residual mitral regurgitation (MR), tricuspid regurgitation (TR), and elevated predischarge transmitral mean pressure gradient (TMPG) on outcomes after mitral transcatheter edge-to-edge repair (TEER) have assessed each parameter in isolation. We sought to examine the prognostic value of combining predischarge MR, TR, and TMPG to study long-term outcomes after TEER.

METHODS AND RESULTS

We reviewed the records of 291 patients who underwent successful mitral TEER at our institution between March 2014 and June 2022. Using well-established outcomes-related cutoffs for predischarge MR (≥moderate), TR (≥moderate), and TMPG (≥5 mm Hg), 3 echo profiles were developed based on the number of risk factors present (optimal: 0 risk factors, mixed: 1 risk factor, poor: ≥2 risk factors). Discrimination of the profiles for predicting the primary composite end point of all-cause mortality and heart failure hospitalization at 2 years was examined using Cox regression. Overall, mean age was 76.7±10.6 years, 43.3% were women, and 53% had primary MR. Two-year event-free survival was 61%. Predischarge TR≥moderate, MR≥moderate, and TMPG≥5 mm Hg were risk factors associated with the primary end point. Compared with the optimal profile, there was an incremental risk in 2-year event-rate with each worsening profile (optimal as reference; mixed profile: hazard ratio (HR), 2.87 [95% CI, 1.71-5.17], P<0.001; poor profile: HR, 3.76 [95% CI, 1.84-6.53], P<0.001). Echocardiographic profile was statistically associated with the 2-year mortality end point (optimal as reference; mixed profile: HR, 3.55 [95% CI, 1.81-5.96], P<0.001; poor profile: HR, 3.39 [95% CI, 2.56-7.33], P=0.02).

CONCLUSIONS

The echocardiographic profile integrating predischarge TR, MR, and TMPG presents a novel prognostic stratification tool for patients undergoing mitral TEER.

Long-Term Impact of Small Mitral Valve Orifice Area after Transcatheter Edge-to-Edge Mitral Valve Repair on Clinical Outcome: A Three-Dimensional Echocardiography Study

BACKGROUND

Iatrogenic mitral stenosis is a complication associated with transcatheter edge-to-edge mitral valve repair. Some reports revealed the impact of mean transmitral pressure gradient after procedure on long-term clinical outcomes. However, the association between prognosis and mitral valve orifice area (MVA) after the procedure has been poorly studied. This study aimed to investigate the association between postprocedural small MVA, derived from three-dimensional (3D) transesophageal echocardiography (TEE), and long-term clinical outcomes in 2 cohorts: the degenerative mitral regurgitation (MR) cohort and the functional MR cohort.

METHODS

This retrospective study assessed 279 consecutive patients with 3D TEE data during transcatheter edge-to-edge mitral valve repair between January 2010 and December 2016. Mitral valve orifice area after device implantation was measured by 3D planimetry. The patients with degenerative and functional MR were stratified separately into 2 groups according to postprocedural MVA: normal MVA (MVA > 1.5 cm2) group and small MVA (MVA ≤ 1.5 cm2) group.

RESULTS

Of the 279 patients, 142 (51%) had degenerative MR and 137 (49%) had functional MR. The number of degenerative MR patients with small MVA was 38, whereas 42 patients were in the functional MR cohort. Patients with small MVA had higher rate of all-cause mortality in the degenerative MR group (log-rank test: P = .01) but not in the functional MR group (log-rank test: P = .52). In multivariate analysis small MVA was independently associated with all-cause mortality but not postprocedural transmitral pressure gradient. Neither small MVA nor transmitral pressure gradient was associated with all-cause mortality in patients with functional MR.

CONCLUSION

Small MVA measured by 3D TEE after transcatheter mitral edge-to-edge repair was associated with poor prognosis in patients with degenerative MR.

Advancements in MitraClip Intervention for Mitral Regurgitation: A Comprehensive Review and Comparative Analysis of Clinical Trials

This comprehensive review explores the evolution and clinical impact of MitraClip intervention in the management of mitral regurgitation. Mitral regurgitation results from dysfunction in the mitral valve (MV) apparatus. The MitraClip Clip Delivery System was approved by the Food and Drug Administration (FDA) in 2013. The discussion delves into the procedural foundation of MitraClip intervention, primarily based on Alfieri's technique of edge-to-edge leaflet approximation. As highlighted by key clinical trials, including Endovascular Valve Edge-to-Edge Repair (EVEREST) II Trial, Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) Trial, and Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation (MITRA-FR) trial, the efficacy and safety of MitraClip were evaluated in comparison to surgical interventions and guideline-directed medical therapy. Notably, the COAPT demonstrated significant benefits in reducing all-cause mortality and heart failure hospitalization, while the MITRA-FR presented contrasting results, emphasizing the importance of patient selection. An analysis of the EVEREST II trial underscores MitraClip's potential to achieve comparable outcomes to surgical intervention, emphasizing its role in reducing mitral regurgitation and improving clinical status. However, limitations and complications, such as device-related issues and the potential impact on future MV surgery, are discussed. The study also explores the evolving landscape of MV interventions, reflecting advancements and the growing acceptance of MitraClip. In conclusion, the MitraClip device represents a significant advancement in the treatment of mitral regurgitation. The data presented highlights its promising results in terms of reduced hospitalization rates, improved in-hospital mortality, and enhanced quality of life for patients. However, challenges remain, and careful consideration of patient selection and underlying pathology is crucial in determining the optimal treatment approach. Ongoing research and clinical experience will continue to refine our understanding of MitraClip's role in the evolving landscape of MV interventions.

Prognosis of Elevated Mitral Valve Pressure Gradient After Transcatheter Edge-to-Edge Repair: Systematic Review and Meta-Analysis

Elevation in mitral valve pressure gradient (MVPG) after mitral valve transcatheter edge-to-edge repair (M-TEER) is common, however, evidence on its prognosis is scarce and debatable. Thus, this study aims to investigate the impact of increased MVPG after M-TEER on outcomes. Studies reporting the associations between the elevated MVPG after M-TEER and outcomes were identified in a systematic search of published literatures. Associations were pooled by meta-analysis using a random-effects model. The primary outcome was the composite of all-cause mortality and heart failure (HF) hospitalization. Seven observational studies with 2,730 patients (mean age, 77.7 ± 9.3 years; male, 64.4%; functional mitral regurgitation [MR], 65.2%) were eligible for the present analysis. M-TEER was performed entirely using the MitraClip system (Abbott), followed by 29.7% of patients having increased MVPG. Elevated postprocedural MVPG was not associated with a higher risk of the primary outcome, compared to low MVPG [hazard ratio (HR) = 1.22; 95% confidence interval (CI) 0.95-1.58; p = 0.12; I2 = 53.5%). However, the prognosis of elevated MVPG was observed in degenerative MR patients (HR = 1.37; 95% CI 1.03-1.84; p = 0.03; I2 = 0%), whereas not in functional MR patients. Patients with low MVPG + high residual MR had a higher risk of the primary outcome than those with high MVPG + low residual MR after M-TEER (HR = 1.50; 95% CI 1.10-2.03; p = 0.01; I2 = 13%). In conclusion, elevated MVPG seems to predict adverse outcomes mainly in patients with degenerative MR. Future studies are needed to prove these findings.

The effect of a smaller spacer in the PASCAL Ace on residual mitral valve orifice area

BACKGROUND

Mitral transcatheter edge-to-edge repair (M-TEER) is an established treatment for functional mitral regurgitation (FMR) associated with a risk of creating iatrogenic stenosis.

OBJECTIVES

To investigate the impact of the P10 and its larger spacer compared to the narrower Ace and its smaller spacer on reduction of mitral valve orifice area (MVOA) during M-TEER.

METHODS

Consecutive patients undergoing M-TEER for treatment of severe FMR were screened retrospectively. Patients with a single PASCAL device implantation within the central segments of the MV leaflets, non-complex anatomy, and baseline MVOA ≥ 3.5cm2 were selected. Intraprocedural transesophageal echocardiography was used to compare MVOA reduction with 3D multiplanar reconstruction and direct planimetry. Device selection did not follow a prespecified MVOA threshold.

RESULTS

Seventy-two patients (81.0 years, IQR {74.3-85.0}) were included. In 32 patients, the P10 was implanted (44.4%). MR severity (p = 0.66), MR reduction (p = 0.73), and body surface area (p = 0.56) were comparable. Baseline MVOA tended to be smaller in P10 patients with the larger spacer (5.0 ± 1.1 vs. 5.4 ± 1.3cm2, p = 0.18), however, residual MVOA was larger in these patients (2.7 ± 0.7 vs. 2.3 ± 0.6cm2, p = 0.03). Accordingly, relative MVOA reduction was significantly less in P10 patients (- 45.9 ± 7.6 vs. - 56.3 ± 7.0%, p < 0.01). Indirect annuloplasty was more pronounced in Ace patients whereas mean transmitral gradients were similar.

CONCLUSION

In FMR patients with non-complex anatomy, the larger spacer of the P10 maintains greater MVOA with similar MR reduction. Hence, the use of the PASCAL Ace device in patients with small MVOAs might correlate with a risk of both clinically relevant orifice reduction and even iatrogenic stenosis.

Periprocedural Echocardiographic Guidance of Transcatheter Mitral Valve Edge-to-Edge Repair Using the MitraClip

Transcatheter edge-to-edge mitral valve repair is a minimally invasive treatment option for selected patients with moderate to severe or severe mitral regurgitation. Although transcatheter edge-to-edge mitral valve repair offers a significant step forward in the management of mitral regurgitation, the rate of procedural-related complications is not trivial. High-quality periprocedural imaging is important for optimal patient selection and procedural success. In this review, we present a step-by-step approach of the recommended echocardiographic views for transcatheter edge-to-edge mitral valve repair.

Multidetector Computed Tomography in Patients Who Underwent Transcatheter Mitral Edge-to-Edge Repair

Multidetector computed tomography (MDCT) can provide valuable information for mitral assessment, but its role in transcatheter mitral edge-to-edge repair (TEER) planning has been poorly elucidated. We aimed to compare MDCT with 3-dimensional transesophageal echocardiography (3D-TEE) for TEER preprocedural evaluation. We analyzed the preprocedural MDCT and 3D-TEE of 108 consecutive patients with mitral regurgitation (MR) who underwent MitraClip implantation. The levels of agreement for the etiology and mechanism of MR, mitral calcification, mitral annulus, and mitral valve orifice area (MVOA) measurements were compared between MDCT and 3D-TEE data. Receiver-operating-characteristic curves were generated for mitral annulus area and MVOA using a low mean transmitral pressure gradient at discharge (<5 mm Hg) as the state variable, and the primary outcome of all-cause mortality or rehospitalization for heart failure at 1 year was compared between MDCT's and 3D-TEE's MVOA <4-cm2 cutoff. Good levels of agreement between MDCT and 3D-TEE were observed for determining the etiology (κ = 0.81) and mechanism (κ = 0.62) of MR but not for grading mitral calcification (κ = 0.31 to 0.35). The correlations between MDCT and 3D-TEE measurements were strong for mitral annulus area (r = 0.90) and good for MVOA (r = 0.73). Furthermore, no significant differences in the area under the receiver-operating-characteristic curve to predict low transmitral pressure gradient at discharge or the primary outcome at 1 year were detected between MDCT- and 3D-TEE-derived parameters (all p >0.05). In conclusion, in patients who underwent TEER with MitraClip, a high degree of agreement for comprehensive evaluation of MR and prediction of clinical outcomes between MDCT and 3D-TEE was observed.

Repairable ex vivo model of functional and degenerative mitral regurgitation

OBJECTIVES

Transcatheter mitral valve repair is an emerging alternative to the surgical repair. This technology requires preclinical studies to assess efficacy in mitigating mitral regurgitation (MR). However, ex vivo MR models are not established. We developed 2 novel repairable models, functional and degenerative, which can quantitatively assess regurgitation and effect of intervention.

METHODS

We used porcine mitral valves and a pulsatile flow circulation system. In the functional MR model, the annulus was immersed in 0.1% collagenase solution and dilated using 3D-printed dilators. To control the regurgitation grade, the sizes of the dilator and silicone sheet in which the valve was sutured to were adjusted. Chordae of P2 were severed in the degenerative model, and the number of severed chordae was adjusted to control the regurgitation grade. Models were repaired using the edge-to-edge or artificial chordae technique.

RESULTS

The mean regurgitant fraction of the moderate-severe functional and degenerative models were 47.9% [standard deviation (SD): 2.2%] and 58.5% (SD: 8.0%), which were significantly reduced to 28.7% (SD: 4.4%) (P < 0.001) and 26.0% (SD: 4.4%) (P < 0.001) after the valve repair procedures. Severe functional model had a mean regurgitant fraction of 59.4% (SD: 6.0%).

CONCLUSIONS

Both functional and degenerative models could produce sufficient MR levels that meet the interventional indication criteria. The repairable models are valuable in evaluating the efficacy of valve repair procedures and devices. The ability to control the amount of regurgitation enhances the versatility and reliability of these models. These reproducible models could expedite the development of novel devices.

Transcatheter edge-to-edge mitral valve repair with extended clip arms for ventricular functional mitral regurgitation

BACKGROUND

The new sizing options of the MitraClip system (Abbott Vascular, Abbott Park, IL, USA) with extended clip arms were recently developed. Its applicability and effectiveness for ventricular functional mitral regurgitation (VFMR) are yet to be investigated.

METHODS

We retrospectively reviewed consecutive patients with symptomatic VFMR who underwent transcatheter edge-to-edge repair between 2018 and 2022 at the Sakakibara Heart Institute. Pre- and post-procedural mitral valve morphologies were assessed using three-dimensional transesophageal echocardiography.

RESULTS

In a total of 104 VFMR patients, the posterior mitral leaflet length was 12.8 ± 2.8 mm and 92 % was indicative of the extended arm (≥9 mm). Although baseline VFMR was more severe in the patients treated with the extended arms (n = 35, XT group) than the patients treated with the standard arms (n = 69, NT group), the decrease in VFMR was greater in the XT group (delta three-dimensional vena contracta area - 43 ± 33 mm2 vs. -31 ± 22 mm2, p = 0.030) and residual VFMR was similar between the groups, with a significantly greater reduction in the mitral annulus anterior-posterior diameter (-4.9 ± 2.2 mm vs -3.1 ± 2.1 mm, p < 0.001) and mitral annulus area in the XT group. The use of extended arms was independently associated with shorter procedure time (81 ± 26 min vs 108 ± 41 min) after adjustment for device generation and the number of clips (p = 0.017).

CONCLUSIONS

Most VFMR patients had enough leaflet lengths for transcatheter edge-to-edge repair using the MitraClip with the extended arms, which was associated with shorter procedure time and a greater decrease in the mitral annular size.

Short-Term Effects of Different Transcatheter Edge-to-Edge Devices on Mitral Valve Geometry

Background Short-term effects on mitral valve (MV) anatomy after transcatheter edge-to-edge repair using the PASCAL system remain unknown. Precise quantification might allow for an advanced analysis of predictors for mean transmitral gradients. Methods and Results Consecutive patients undergoing transcatheter edge-to-edge repair for secondary mitral regurgitation using PASCAL or MitraClip systems were included. Quantification of short-term MV changes throughout the cardiac cycle was performed using peri-interventional 3-dimensional MV images. Predictors for mean transmitral gradients were identified in univariable and multivariable regression analysis. Long-term results were described during 1-year follow-up. A total of 100 patients undergoing transcatheter edge-to-edge repair using PASCAL (n=50) or MitraClip systems (n=50) were included. Significant reductions of anterior-posterior diameter, annular circumference, and area throughout the cardiac cycle were found in both cohorts (P<0.05 for all). Anatomic MV orifice area remained larger in the PASCAL cohort in mid (2.8±1.0 versus 2.4±0.9 cm2; P=0.049) and late diastole (2.7±1.1 versus 2.2±0.8 cm2; P=0.036) compared with the MitraClip cohort. Besides a device-specific profile of independent predictor of mean transmitral gradients, reduction of middiastolic anatomic MV orifice area was identified as an independent predictor in both the PASCAL (β=-0.410; P=0.001) and MitraClip cohorts (β=-0.318; P=0.028). At follow-up, reduction of mitral regurgitation grade to mild or less was more durable in the PASCAL cohort (90% versus 72%; P=0.035). Conclusions PASCAL and MitraClip showed comparable short-term effects on MV geometry. However, PASCAL might better preserve MV function and demonstrated more durable mitral regurgitation reduction during follow-up. Identification of independent predictors for mean transmitral gradients might potentially help to guide device selection in the future.

Multimodality imaging for patient selection, procedural guidance, and follow-up of transcatheter interventions for structural heart disease: a consensus document of the EACVI Task Force on Interventional Cardiovascular Imaging: part 1: access routes, transcatheter aortic valve implantation, and transcatheter mitral valve interventions

Transcatheter therapies for the treatment of structural heart diseases (SHD) have expanded dramatically over the last years, thanks to the developments and improvements of devices and imaging techniques, along with the increasing expertise of operators. Imaging, in particular echocardiography, is pivotal during patient selection, procedural monitoring, and follow-up. The imaging assessment of patients undergoing transcatheter interventions places demands on imagers that differ from those of the routine evaluation of patients with SHD, and there is a need for specific expertise for those working in the cath lab. In the context of the current rapid developments and growing use of SHD therapies, this document intends to update the previous consensus document and address new advancements in interventional imaging for access routes and treatment of patients with aortic stenosis and regurgitation, and mitral stenosis and regurgitation.

Impact of Mitral Regurgitation Etiology on Mitral Surgery After Transcatheter Edge-to-Edge Repair: From the CUTTING-EDGE Registry

BACKGROUND

Although >150,000 mitral TEER procedures have been performed worldwide, the impact of MR etiology on MV surgery after TEER remains unknown.

OBJECTIVES

The authors sought to compare outcomes of mitral valve (MV) surgery after failed transcatheter edge-to-edge repair (TEER) stratified by mitral regurgitation (MR) etiology.

METHODS

Data from the CUTTING-EDGE registry were retrospectively analyzed. Surgeries were stratified by MR etiology: primary (PMR) and secondary (SMR). MVARC (Mitral Valve Academic Research Consortium) outcomes at 30 days and 1 year were evaluated. Median follow-up was 9.1 months (IQR: 1.1-25.8 months) after surgery.

RESULTS

From July 2009 to July 2020, 330 patients underwent MV surgery after TEER, of which 47% had PMR and 53.0% had SMR. Mean age was 73.8 ± 10.1 years, median STS risk at initial TEER was 4.0% (IQR: 2.2%-7.3%). Compared with PMR, SMR had a higher EuroSCORE, more comorbidities, lower LVEF pre-TEER and presurgery (all P < 0.05). SMR patients had more aborted TEER (25.7% vs 16.3%; P = 0.043), more surgery for mitral stenosis after TEER (19.4% vs 9.0%; P = 0.008), and fewer MV repairs (4.0% vs 11.0%; P = 0.019). Thirty-day mortality was numerically higher in SMR (20.4% vs 12.7%; P = 0.072), with an observed-to-expected ratio of 3.6 (95% CI: 1.9-5.3) overall, 2.6 (95% CI: 1.2-4.0) in PMR, and 4.6 (95% CI: 2.6-6.6) in SMR. SMR had significantly higher 1-year mortality (38.3% vs 23.2%; P = 0.019). On Kaplan-Meier analysis, the actuarial estimates of cumulative survival were significantly lower in SMR at 1 and 3 years.

CONCLUSIONS

The risk of MV surgery after TEER is nontrivial, with higher mortality after surgery, especially in SMR patients. These findings provide valuable data for further research to improve these outcomes.

Contemporary treatment of mitral valve disease with transcatheter mitral valve implantation

BACKGROUND

Transcatheter mitral valve implantation (TMVI) with self-expanding (SAV) or balloon-expandable (BAV) valves are rising as promising treatment options for high-risk patients with symptomatic mitral valve (MVD) disease unsuitable for alternative treatment options.

AIMS

The aim of this study was to examine the clinical, procedural and outcome parameters of patients undergoing SAV or BAV for MVD.

METHODS

In this observational and single-center case series, fifteen consecutive patients treated with the Tendyne Mitral Valve System (SAV) and thirty-one patients treated with SAPIEN prosthesis (BAV) were included.

RESULTS

The patients (aged 78 years [interquartile range (IQR): 65.5 to 83.1 years], 41% women, EuroSCORE II 10.3% [IQR: 5.5 to 17.0%] were similar regarding baseline characteristics, despite a higher rate of prior heart valve surgery and prevalence of MV stenosis in the SAV-group. At discharge, the SAV-group had a mean transvalvular gradient of 4.2 mmHg, whereas the BAV-group had a mean transvalvular gradient of 6.2 mmHg. None or trace paravalvular leakage (PVL) was assessed in 85% in SAV-group and 80% in the BAV-group. 320 day all-cause and cardiac mortality rates were comparable in both groups (SAV: 26.7% vs BAV: 20%, p = 0.60). Four deaths occurred early in the SAV-group until 32 days of follow-up.

CONCLUSIONS

In high-risk patients with MVD, TMVI presents a promising treatment option with encouraging mid-term outcomes and good valve durability. TMVI either with BAV or SAV may be developed to an established treatment option.

Improved mid-term stability of MR reduction with an increased number of clips after percutaneous mitral valve repair in functional MR

Background

Percutaneous mitral valve repair (PMVR) has evolved to be a standard procedure in suitable patients with mitral regurgitation (MR) not accessible for open surgery. Here, we analyzed the influence of the number and positioning of the clips implanted during the procedure on MR reduction analyzing also sub-collectives of functional and degenerative MR (DMR).

Results

We included 410 patients with severe MR undergoing PMVR using the MitraClip® System. MR and reduction of MR were analyzed by TEE at the beginning and at the end of the PMVR procedure. To specify the clip localization, we sub-divided segment 2 into 3 sub-segments using the segmental classification of the mitral valve.

Results

We found an enhanced reduction of MR predominantly in DMR patients who received more than one clip. Implantation of only one clip led to a higher MR reduction in patients with functional MR (FMR) in comparison to patients with DMR. No significant differences concerning pressure gradients could be observed in degenerative MR patients regardless of the number of clips implanted. A deterioration of half a grade of the achieved MR reduction was observed 6 months post-PMVR independent of the number of implanted clips with a better stability in FMR patients, who got 3 clips compared to patients with only one clip.

Conclusions

In patients with FMR, after 6 months the reduction of MR was more stable with an increased number of implanted clips, which suggests that this specific patient collective may benefit from a higher number of clips.

Prognostic Value of Tricuspid Valve Gradient After Transcatheter Edge-to-Edge Repair: Insights From the TriValve Registry

BACKGROUND

Data regarding the impact of the tricuspid valve gradient (TVG) after tricuspid transcatheter edge-to-edge repair (TEER) are scarce.

OBJECTIVES

This study sought to evaluate the association between the mean TVG and clinical outcomes among patients who underwent tricuspid TEER for significant tricuspid regurgitation.

METHODS

Patients with significant tricuspid regurgitation who underwent tricuspid TEER within the TriValve (International Multisite Transcatheter Tricuspid Valve Therapies) registry were divided into quartiles based on the mean TVG at discharge. The primary endpoint was the composite of all-cause mortality and heart failure hospitalization. Outcomes were assessed up to the 1-year follow-up.

RESULTS

A total of 308 patients were included from 24 centers. Patients were divided into quartiles of the mean TVG as follows: quartile 1 (n = 77), 0.9 ± 0.3 mm Hg; quartile 2 (n = 115), 1.8 ± 0.3 mm Hg; quartile 3 (n = 65), 2.8 ± 0.3 mm Hg; and quartile 4 (n = 51), 4.7 ± 2.0 mm Hg. The baseline TVG and the number of implanted clips were associated with a higher post-TEER TVG. There was no significant difference across TVG quartiles in the 1-year composite endpoint (quartiles 1-4: 35%, 30%, 40%, and 34%, respectively; P = 0.60) or the proportion of patients in New York Heart Association class III to IV at the last follow-up (P = 0.63). The results were similar after adjustment for clinical and echocardiographic characteristics (composite endpoint quartile 4 vs quartile 1-quartile 3 adjusted HR: 1.05; 95% CI: 0.52-2.12; P = 0.88) or exploring post-TEER TVG as a continuous variable.

CONCLUSIONS

In this retrospective analysis of the TriValve registry, an increased discharge TVG was not significantly associated with adverse outcomes after tricuspid TEER. These findings apply for the explored TVG range and up to the 1-year follow-up. Further investigations on higher gradients and longer follow-up are needed to better guide the intraprocedural decision-making process.

Transcatheter Mitral Valve Repair via MitraClip in Patients Aged <65 Years: Multicentre 2-year Outcomes

Background

Transcatheter mitral valve repair (TMVR) using the MitraClip has become a well-established interventional therapy and is usually performed in elderly patients. The objective of this study was to assess 2-year clinical outcomes of TMVR in patients aged <65 years at three heart centres with severe mitral regurgitation (MR) and no surgical options.

Methods

A retrospective study analysed data of 36 patients aged <65 years treated with TMVR . All patients were refused surgery by Heart Team decision. Baseline MR was assessed by biplane vena contracta width in two perpendicular views (mean 8.35 ± 1.87 mm). Degenerative MR was detected in 11 patients (30.6%); functional MR was detected in 25 patients (69.4%).

Results

Acute procedural success was accomplished in 88.9% of patients. No procedure-related mortality during the first 30 days was detected. Over an average of 2 years of follow-up, all-cause mortality was 19.4% and cardiovascular death was 11.1% owing to advanced heart failure. The average follow-up period was 25.8 months (median was 20 months). Statistically significant difference (p-value <0.01) was detected for N-terminal prohormone of brain natriuretic peptide (pg/ml) at baseline (mean 9,870 ± 10,819; median 7,748) compared to follow-up visits (mean 7,645 ± 11,292; median 3,263). New York Heart Association functional class improvement was achieved in 69% of patients. A second intervention (reclipping) was required in two patients to correct recurrent significant MR.

Conclusion

TMVR in patients aged <65 years refused surgical repair provides satisfactory clinical outcomes at 2 years. Future studies should evaluate the outcomes of MitraClip in this population in a larger cohort.

Prognostic value of mitral valve haemodynamic parameters obtained by intraprocedural echocardiography in transcatheter edge-to-edge repair

AIMS

To assess whether intraprocedural transesophageal echocardiographic (TEE)-derived haemodynamic parameters predict outcomes in patients undergoing transcatheter edge-to-edge repair (TEER) for mitral regurgitation (MR).

METHODS AND RESULTS

This is a single-centre, retrospective analysis encompassing 458 (IQR, 104-1035) days of follow-up after 926 consecutive patients [481 (52%) with functional MR] referred to an isolated mitral TEER between 2013 and 2020. Cases without actual clip deployment, or in whom prior mitral procedures had taken place, were excluded. The primary outcome was the combined rate of all-cause mortality or heart failure (HF) hospitalizations. Secondary endpoints included single components of the primary outcome, as well as MR severity at one month and one year following the procedure. A multivariable analysis identified two intraprocedural echocardiographic observations made after clip deployment as independent predictors of the primary outcome: an above mild MR (HR for whole study period 1.49, 95% CI 1.05-2.13, P = 0.026) and a 100% or more increase from baseline in the transmitral mean pressure gradient (TMPG) (HR for whole study period 1.32, 95% CI 1.01-1.72, P = 0.039). Also, MR grade of above mild and the absence of a normal pulmonary venous flow pattern (PVFP) bilaterally were associated with an increased risk for HF hospitalizations and greater-than-mild 1-month MR. No prognostic role was demonstrated for the change in MR severity, the absolute TMPG, or the mere improvement in PVFP.

CONCLUSION

Immediate post-TEER MR severity and the relative change in TMPG are predictive of clinical and echocardiographic outcomes following the procedure.

Transcatheter edge-to-edge mitral valve repair in mitral regurgitation: current status and future prospects

INTRODUCTION

Mitral regurgitation (MR) is associated with substantial morbidity and mortality. Within the past 15 years, mitral valve edge-to-edge repair (M-TEER) has developed from an experimental approach to a guideline-recommended, safe, and effective treatment option for patients with severe primary or secondary mitral regurgitation.

AREAS COVERED

This review covered relevant publications of M-TEER and summarizes the development of M-TEER devices within the last 15 years. It outlines anatomical challenges which drove the evolution of M-TEER devices, provides an overview about the current state of clinical application and research, and offers an outlook into the future of transcatheter mitral valve treatment.

EXPERT OPINION

The development and refinement of new M-TEER device generations offer the possibility to treat a wide range of mitral valve anatomies. Choosing the best device for the individual anatomic properties of the patients and considering comorbidities is the key to maximized MR reduction, minimalized complication rates, and thus optimized postinterventional prognosis. Independent from prognostic implications, quality of life has become an important patient-centered outcome that can be improved by M-TEER in virtually all patients treated.

The impact of baseline transmitral diastolic mean gradient on left atrial pressure reduction in patients undergoing transcatheter mitral valve edge-to-edge repair

BACKGROUND

Elevated transmitral gradient post transcatheter mitral valve edge-to-edge repair (TEER) has been associated with worse outcomes. Whether an elevated baseline transmitral diastolic mean gradient (MG) ≥5 mmHg is associated with hemodynamic outcomes after TEER is unknown.

METHODS

A total of 164 consecutive patients undergoing TEER at Mayo Clinic between June 2014 and May 2018 were analyzed in this retrospective study. Baseline demographics, as well as clinical, echocardiographic, and procedural data were obtained. Data on direct left atrial pressure (LAP) before and after TEER were recorded. Logistic regression models were constructed to evaluate the association between preprocedure transmitral diastolic mean gradient (pre-MG) and (1) improvement in LAP following TEER, (2) postprocedure transmitral diastolic mean gradient (post-MG). A decrease in LAP post TEER was considered an improvement in hemodynamic response. Pre-MG was categorized as: ≥5 and <5 mmHg.

RESULTS

Median age of the cohort was 81.5 years (Q1: 76.3, Q3: 87) and 34% were female. At baseline, median transmitral diastolic MG was 4 mmHg (Q1: 3, Q3: 5) and median LAP was 19 mmHg (Q1:16, Q3: 23.5). In a multivariable model, adjusted for age and sex, patients with pre-MG ≥ 5 mmHg were less likely to see an improvement in LAP post TEER (adjusted odds ratio [aOR]: 0.22, 95% confidence interval [CI]: 0.09, 0.55; p = 0.001) and more likely to have elevated post-MG (aOR; 7.08, 95% CI: 2.93, 17.13; p < 0.001).

CONCLUSION

Higher pre-MG (≥5 mmHg) was associated with a lower reduction in LAP and higher residual transmitral gradient following TEER suggesting other potential contributors to increased LAP besides mitral regurgitation as a cause of elevated baseline MG.

Mitral valve transcatheter edge-to-edge repair

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, results in reduced quality of life, heart failure, and increased mortality. Mitral valve transcatheter edge-to-edge repair (M-TEER) has matured considerably as a non-surgical treatment option since its commercial introduction in Europe in 2008. As a result of major device and interventional improvements, as well as the accumulation of experience by the interventional cardiologists, M-TEER has emerged as an important therapeutic strategy for patients with severe and symptomatic MR in the current European and American guidelines. Herein, we provide a comprehensive up-do-date overview of M-TEER. We define preprocedural patient evaluation and highlight key aspects for decision-making. We describe the currently available M-TEER systems and summarise the evidence for M-TEER in both primary mitral regurgitation (PMR) and secondary mitral regurgitation (SMR). In addition, we provide recommendations for device selection, intraprocedural imaging and guiding, M-TEER optimisation and management of recurrent MR. Finally, we provide information on major unsolved questions and "grey areas" in M-TEER.

Significance of Spontaneous Echocardiographic Contrast in Transcatheter Edge-to-Edge Repair for Mitral Regurgitation

BACKGROUND

Spontaneous echocardiographic contrast (SEC) in the left atrium can occur with transcatheter edge-to-edge repair (TEER), but the clinical significance is unknown.

METHODS

The authors examined the clinical association of the procedural appearance of SEC in 316 patients (median age, 82 years; interquartile range, 76-86 years; 43.4% women) undergoing TEER with the MitraClip for mitral regurgitation. Acute, 30-day, and 2-year clinical outcomes were analyzed.

RESULTS

SEC was common, occurring following device implantation in 106 patients (34%). Although the occurrence of SEC was not related to clinical characteristics, such as atrial fibrillation, anticoagulant use, or left ventricular function, there was a strong relation to beneficial outcomes with TEER. The frequency of optimal reduction in mitral regurgitation was higher in patients who had SEC (99.1% vs 72.9%, P < .001). Survival was greater, with a 2-year estimate for freedom from all-cause mortality of 88.4% versus 71.5% (log-rank P = .004). Importantly, the higher survival observed in patients with SEC was present without increased rates of procedural complications or stroke and remained significant in multivariate analyses that adjusted for baseline clinical and echocardiographic variables (P = .01).

CONCLUSIONS

The occurrence of SEC in patients with TEER is associated with beneficial acute and intermediate-term outcomes.

Early Outcomes of 2 Mitral Valve Transcatheter Leaflet Approximation Devices: A Propensity Score-Matched Multicenter Comparison

BACKGROUND

In addition to the edge-to-edge MitraClip repair system, the edge-to-spacer PASCAL repair system was approved for percutaneous treatment of severe mitral regurgitation (MR). Comparative data are lacking.

OBJECTIVES

The aim of this study was to compare procedural and short-term safety and efficacy of 2 leaflet-based transcatheter mitral valve repair systems.

METHODS

Procedural and 30-day outcomes were investigated in a propensity score-matched cohort of 307 PASCAL and 307 MitraClip patients at 10 sites. Matching criteria included sex, age, left ventricular ejection fraction, New York Heart Association functional class, MR etiology, left ventricular end-diastolic diameter, left atrial volume index, and vena contracta width. The primary efficacy endpoints were technical success and degree of residual MR at discharge. The primary safety endpoint was the rate of major adverse events (MAE).

RESULTS

Technical success was 97.0% in the PASCAL group and 98.0% in the MitraClip group (P = 0.624). MR ≤2+ at discharge was comparable in both groups (PASCAL: 93.8% vs MitraClip: 92.4%; P = 0.527), with more patients exhibiting MR ≤1+ in the PASCAL group (70.5% vs 56.6%; P < 0.001). The postprocedural mean gradient was significantly higher in the MitraClip group (3.3 ± 1.5 mm Hg vs 3.9 ± 1.7 mm Hg; P < 0.001). At 30 days, all-cause mortality and MAE rates were similar (mortality: 1.7% vs 3.3%; P = 0.299; MAE: 3.9% vs 5.2%; P = 0.562).

CONCLUSIONS

In this first large propensity score-matched comparison, procedural success rates and MAE did not differ significantly between patients treated with the PASCAL or MitraClip valve repair system. Procedural results with less than moderate MR and no elevated transmitral gradient were more common in the PASCAL group, which might have an impact on long-term outcome.

Long-term outcomes of papillary muscle relocation anteriorly for functional mitral regurgitation

OBJECTIVES

This study aimed to evaluate the outcomes of the patients who underwent restrictive annuloplasty (RA) plus papillary muscle relocation anteriorly (PMR-A) with the risk factors in mitral valve repair for functional mitral regurgitation (FMR).

METHODS

Eighty-six patients underwent mitral valve repair with RA for FMR. Thirty-five of them received additional bilateral papillary muscle relocation for severe leaflet tethering. The papillary muscles were relocated posteriorly (PMR-P) early in the study. Then, in the later period, the technique was modified to PMR-A, in which the papillary muscles were relocated anteriorly for 24 cases. The survival of the patients undergoing RA + PMR-A was examined retrospectively, adjusting for differences in patient background.

RESULTS

Twenty-three deaths were observed during the follow-up period out of the 86 cases. Independent preoperative risk factors for survival were left ventricular ejection fraction, patient age and B-type natriuretic peptide (BNP) level. Among the patients with BNP <1000 pg/ml, 5-year survival after RA plus PMR-A was 84.7%, while RA alone was 78.6% and RA + PMR-P 57.1%. Cox proportional hazards regression adjusted for the preoperative risk factors showed a significantly higher hazard ratio of RA + PMR-P to RA + PMR-A (12.77, P = 0.011), while the hazard ratio of RA alone to RA + PMR-A was not significantly different. Furthermore, reverse remodelling of the left ventricle was observed for 3 years only in RA + PMR-A.

CONCLUSIONS

Long-term survival for patients who underwent RA plus bilateral PMR-A was promising. Patients with significantly higher BNP had lower survival after valve repair for FMR.

Outcomes in Patients With High Transmitral Gradient After Mitral Valve Transcatheter Edge-to-Edge Repair for Mitral Regurgitation

Despite being highly effective in reducing residual mitral regurgitation and improving outcomes, mitral valve transcatheter edge-to-edge repair (MV-TEER) may be associated with high postprocedural residual mitral gradient (rMG). Conflicting results have been reported regarding the relation between rMG and adverse events. This study aimed to evaluate the predictors and the impact of elevated rMG after MV-TEER on clinical events in patients with functional mitral regurgitation (FMR) at 2 years follow-up. We selected a cohort of 864 patients with FMR who were treated with MV-TEER enrolled in the multicentre Italian Society of Interventional Cardiology (GISE) registry of transcatheter treatment of mitral valve regurgitation (GIOTTO). Patients were stratified into tertiles according to rMG. The primary clinical end point was a composite of all-cause death and hospitalization because of heart failure at 2-year follow-up. Overall, 269 patients (31.5%) with an rMG <3 mm Hg, 259 (30.3%) with an rMG ≥3/<4 mm Hg, and 326 (38.2%) with an rMG ≥4 mm Hg were considered. At multivariate logistic regression, ischemic FMR etiology, baseline MG, and the number of implanted clips were independent predictors of an rMG ≥4 mm Hg. Clinical follow-up was available in 570 patients (63.2%). Patients with an rMG ≥4 mm Hg experienced higher rates of the composite end point than patients of the other tertiles (51.1%, vs 42.3% vs 40.8% log-rank test: p = 0.033). In multivariate Cox's regression, both rMG ≥4 mm Hg (hazard ratio 1.54, 95% confidence interval 1.14 to 2.08) and residual mitral regurgitation ≥2+ (hazard ratio 1.36, 95% confidence interval 1.01 to 1.83) were independent predictors of adverse events at 2-year follow-up. In conclusion, we demonstrated that real-world patients who underwent MV-TEER who show an rMG ≥4 mm Hg are at higher risk of death or hospitalization because of heart failure during a 2-year follow-up. Further studies will be needed to confirm our results.

Effect of transcatheter edge-to-edge repair device position on diastolic hemodynamic parameters: An echocardiography-based simulation study

Background

Transcatheter edge-to-edge repair (TEER) has developed from innovative technology to an established treatment strategy of mitral regurgitation (MR). The risk of iatrogenic mitral stenosis after TEER is, however, a critical factor in the conflict of interest between maximal reduction of MR and minimal impairment of left ventricular filling. We aim to investigate systematically the impact of device position on the post treatment hemodynamic outcome by involving the patient-specific segmentation of the diseased mitral valve.

Materials and methods

Transesophageal echocardiographic image data of ten patients with severe MR (age: 57 ± 8 years, 20% female) were segmented and virtually treated with TEER at three positions by using a position based dynamics approach. Pre- and post-interventional patient geometries were preprocessed for computational fluid dynamics (CFD) and simulated at peak-diastole with patient-specific blood flow boundary conditions. Simulations were performed with boundary conditions mimicking rest and stress. The simulation results were compared with clinical data acquired for a cohort of 21 symptomatic MR patients (age: 79 ± 6 years, 43% female) treated with TEER.

Results

Virtual TEER reduces the mitral valve area (MVA) from 7.5 ± 1.6 to 2.6 ± 0.6 cm2. Central device positioning resulted in a 14% smaller MVA than eccentric device positions. Furthermore, residual MVA is better predictable for central than for eccentric device positions (R2 = 0.81 vs. R2 = 0.49). The MVA reduction led to significantly higher maximal diastolic velocities (pre: 0.9 ± 0.2 m/s, post: 2.0 ± 0.5 m/s) and pressure gradients (pre: 1.5 ± 0.6 mmHg, post: 16.3 ± 9 mmHg) in spite of a mean flow rate reduction by 23% due to reduced MR after the treatment. On average, velocities were 12% and pressure gradients were 25% higher with devices in central compared to lateral or medial positions.

Conclusion

Virtual TEER treatment combined with CFD is a promising tool for predicting individual morphometric and hemodynamic outcomes. Such a tool can potentially be used to support clinical decision making, procedure planning, and risk estimation to prevent post-procedural iatrogenic mitral stenosis.

Complications of the Percutaneous Mitral Valve Edge-To-Edge Repair: Role of Transesophageal Echocardiography

The use of transcatheter edge-to-edge repair for the treatment of mitral regurgitation has markedly increased in the last few years. The rate of adverse events related to the procedure is low; however, some of the complications that may occur are potentially dangerous. Due to the growing popularity of the technique, which is no longer limited to high-volume centers, knowledge of the complications related to the procedure is fundamental. Transesophageal echocardiography has a key role in the guidance of the intervention while allowing for the avoidance of most of these adverse events, as well as enabling us to diagnose them early. In this article, we review the main complications that might present during a transcatheter mitral edge-to-edge repair procedure (tamponade, thromboembolic events, single leaflet device attachment, device embolization, vascular injury…) while highlighting key aspects of transesophageal echocardiographic monitoring in the prevention and prompt diagnosis of these complications.

Transesophageal Echocardiography For The Assessment of Left Atrial Pressure After Trans-Septal Mitral Valve Interventions

The measure of left atrial pressure (LAP) is an ideal marker for the clinical efficacy of transcatheter mitral valve intervention. Currently, only the invasive measurement of LAP (i-LAP) is available and no echocardiographic methods are reliable in the setting of transcatheter mitral valve intervention. This study sought to validate a new echocardiographic method for the estimation of LAP (e-LAP) by comparing it with i-LAP. During percutaneous edge-to-edge procedure with MitraClip, the i-LAP was routinely monitored. Across the iatrogenic interatrial septum defect, the flow was sampled with continuous-wave Doppler echocardiography for deriving the mean pressure gradient between the left atrium and the right atrium, and the central venous pressure was added to obtain the e-LAP. The correlation between the measures derived from these 2 methods was explored. A total of 34 consecutive patients were included. Intraclass correlation coefficient between e-LAP and i-LAP was high (intraclass correlation coefficient [95% confidence interval] 0.809 [0.625 to 0.902], R Pearson 0.6, p <0.001); a bias of -1.3 mm Hg for e-LAP versus i-LAP was found (p = 0.32). The median follow-up was 108 days (interquartile range 40 to 264). No death occurred and 6 patients were rehospitalized for heart failure. Postimplant e-LAP was correlated with rehospitalization at follow-up (hazard ratio 1.46, 95% confidence interval 1.022 to 2.1, p = 0.038). A cut-off value of 9.5 mm Hg for the e-LAP was identified as predictor of rehospitalization for heart failure. The evaluation of e-LAP has optimal reliability compared with i-LAP; a value more than 9.5 mm Hg was found to be related to higher risk of events at short follow-up.

Treatment of secondary mitral regurgitation by transcatheter edge-to-edge repair using MitraClip

Transcatheter edge-to-edge repair (TEER) is becoming the standard invasive treatment for ventricular functional mitral regurgitation (MR). It is necessary to determine the severity of MR before treatment with MitraClip; however, the severity of secondary MR is usually underestimated compared with that of primary MR and varies temporally. Therefore, to accurately determine the severity of MR, it is important to correctly use the algorithm of the guidelines for valvular heart disease and aggressively perform stress echocardiography. Before performing TEER, the difficulty of the procedure should be evaluated. First, morphological features that make TEER unsuitable, such as cleft of the mitral leaflet, mitral stenosis (MS), or perforation of the mitral leaflet, should be checked. The mitral valve orifice area, transmitral valve pressure gradient, coaptation depth, coaptation length, and posterior leaflet length should be measured to determine the difficulty of the procedure based on the inclusion criteria of Endovascular Valve Edge-to-Edge Repair Study II and the German consensus. After MitraClip implantation, in addition to assessing the severity of MS and residual MR, the pulmonary venous flow pattern and stroke volume should be evaluated to comprehensively assess whether TEER improves the hemodynamics. MitraClip has also been used to treat atrial functional MR, another type of secondary MR. Several reports suggest that MitraClip is effective for atrial functional MR; however, evidence is still being accumulated.

Prognostic Value of Increased Mitral Valve Gradient After Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation

OBJECTIVES

This study sought to evaluate the prognostic value of an increased mean mitral valve pressure gradient (MVG) in patients with primary mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER).

BACKGROUND

Conflicting data exist regarding impact of increased mean MVG on outcomes after TEER.

METHODS

This study included 419 patients with primary MR (mean age 80.6 ± 10.4 years; 40.6% female) who underwent TEER. Patients were divided into quartiles (Qs) based on discharge echocardiographic mean MVG. Primary outcome was the composite endpoint of all-cause mortality and heart failure hospitalization. Secondary outcomes included all-cause mortality and the secondary composite endpoint of all-cause mortality, heart failure hospitalization, and mitral valve reintervention.

RESULTS

The median number of MitraClips used was 2 per patient. MR reduction ≤moderate was achieved in 407 (97.1%) patients. Mean MVG was 1.9 ± 0.3 mm Hg, 3.0 ± 0.1 mm Hg, 4.0 ± 0.1 mm Hg, and 6.0 ± 1.2 mm Hg in Q1, Q2, Q3, and Q4, respectively. There was no significant differences across quartiles in the primary outcome (15.4%, 19.6%, 22.0%, and 21.9% in Q1-Q4, respectively; P = 0.63), all-cause mortality (15.9% vs 18.6% vs 19.4% vs 17.1%, respectively; P = 0.91), and the secondary composite endpoint at 2 years (33.3% vs 29.5% vs 22.0% vs 31.6%, respectively; P = 0.37). After multivariate adjustment for baseline clinical and procedural variables, the mean MVG in Q4 compared with Q1 to Q3 was not independently associated with the primary outcome (HR: 1.22; 95% CI: 0.82-1.83; P = 0.33), all-cause mortality, and the secondary composite endpoint.

CONCLUSIONS

Increased mean MVG was not independently associated with adverse events after TEER in patients with primary MR.

Long-Term Outcomes of Patients With Elevated Mitral Valve Pressure Gradient After Mitral Valve Edge-to-Edge Repair

OBJECTIVES

The aim of this study was to investigate the adverse impact of elevated postprocedural mitral valve pressure gradient (MPG) on outcome in a real-world population of patients with severe mitral regurgitation (MR) who underwent transcatheter mitral valve edge-to-edge repair (TEER).

BACKGROUND

TEER has become a routine treatment alternative for patients with severe MR at high surgical risk. The consequences of elevated MPG after TEER have been subject to controversial debates.

METHODS

All consecutive patients undergoing TEER for either severe degenerative MR (DMR) or functional MR (FMR) at a high-volume center between September 2008 and January 2020 were prospectively included and followed periodically. Postprocedural MPG by discharge transthoracic echocardiography was considered elevated at ≥5 mm Hg. The primary combined endpoint was death or heart failure rehospitalization after 5 years.

RESULTS

A total of 713 patients undergoing TEER (DMR, n = 265; FMR, n = 445) were included. Elevated postprocedural MPG was present in 37.0% of those with DMR (n = 98) and 22.0% of those with FMR (n = 98). In contrast to patients with FMR, 6-minute walk distance did not improve in patients with DMR with elevated MPG. Kaplan-Meier analyses did not demonstrate significant differences for the primary endpoint in patients with DMR (low vs elevated MPG, 67.3% vs 74.4%; P = 0.06) and those with FMR (78.6% vs 74.8%; P = 0.54). After adjustment, elevated MPG was an independent predictor of the primary endpoint in patients with DMR (HR: 1.59; 95% CI: 1.03-2.45; P = 0.034) but not in those with FMR (HR: 0.87; 95% CI: 0.63-1.22; P = 0.43).

CONCLUSIONS

Elevated postprocedural MPG is an independent predictor of adverse clinical and functional outcomes in patients with DMR but not in those with FMR.

Clinical and echocardiographic differences in three different etiologies of severe mitral stenosis

BACKGROUND

In our institute, the causes of mitral stenosis (MS) are generally categorized into three main etiologies-rheumatic MS (RMS), degenerative MS with annular and leaflet calcification, and post-clip MS as a consequence of transcatheter mitral valve repair with clips for treating mitral regurgitation. However, clinical differences among the three etiologies are uncertain.

METHODS

We retrospectively assessed 293 consecutive patients (53 with RMS, 118 with degenerative MS, and 122 with post-clip MS) who had a three-dimensional (3D) transesophageal echocardiography (TEE) derived mitral valve orifice area (MVA) of ≤1.5 cm² , and a mean transmitral pressure gradient of ≥5 mmHg on transthoracic echocardiography.

RESULTS

Although there was no difference in 3D-TEE-derived MVA among the three groups, patients with post-clip MS had a significantly lower mean transmitral pressure gradient compared to those with either of the other two types of MS (10.8 ([7.9-15.2] mmHg vs. 9.6 [7.3-12.5] mmHg vs. 6.9 [6.0-9.2] mmHg; p < .001). Patients with RMS had a higher prevalence of dyspnea. The independent determinants of dyspnea were pressure half time in RMS, 3D-TEE-derived MVA and estimated right atrial pressure in degenerative MS, and left ventricle ejection fraction in post-clip MS.

CONCLUSIONS

Patients with post-clip MS had the lowest mean transmitral pressure gradient, and patients with RMS had the highest prevalence of dyspnea, despite having a similar 3D-TEE-derived MVA. The determinants of dyspnea were different among the three etiologies of MS.

Transcatheter edge-to-edge mitral valve repair in patients with mitral annulus calcification

BACKGROUND

MAC is commonly found in patients affected with MR, and it is associated with high morbidity, mortality and worse cardiac surgical outcomes. Transcatheter edge-to-edge repair could be an alternative treatment, although there is little evidence in this population.

AIMS

The aim of this study was to analyse the safety, efficacy and durability of MitraClip implantation in patients affected with mitral regurgitation (MR) and mitral annulus calcification (MAC).

METHODS

We analysed the outcomes of 61 suitable patients affected with severe MR and moderate or severe MAC (the "MAC" group) and 791 patients with no or mild MAC (the "NoMAC" group) treated with the MitraClip device.

RESULTS

Procedural success was similar (91.8% vs 95.1%, p=0.268, in MAC and NoMAC, respectively), with a very low rate of complications. At one-year follow-up, 90.6% of MAC and 79.5% of NoMAC patients had MR grade ≤2 (p=0.129), 80% in both groups remained in NYHA Functional Class ≤II, and a significant reduction in cardiac readmissions was observed (65% vs 78% in MAC vs NoMAC, p=0.145). One-year mortality tended to be higher in MAC patients (19.7% vs 11.3%, p=0.050), with no difference in cardiovascular mortality (15.3% vs 9.2%, p=0.129).

CONCLUSIONS

MitraClip use in selected patients with moderate or severe MAC is safe, feasible and achieves good clinical and echocardiographic results at one-year follow-up.

Real-world anticoagulatory treatment after percutaneous mitral valve repair using MitraClip: a retrospective, observational study on 1300 patients

Aims

This study sought to investigate current anticoagulatory treatment patterns and clinical outcome in patients undergoing transcatheter mitral valve repair (MitraClip).

Methods and results

In a retrospective study of a German claims database (InGef research database), anticoagulatory treatment regimens were assessed using any drug prescription post discharge within the first 90 days after MitraClip procedure. Clinical events between 30 days and 6 months were examined by treatment regime. The study population comprised 1342 patients undergoing MitraClip procedure between 2014 and 2018. 22.4% received antiplatelet monotherapy, 20.8% oral anticoagulation (OAC) plus antiplatelet therapy, 19.4% OAC monotherapy, 11.7% dual antiplatelet therapy, 2.8% triple therapy and 21.0% did not receive any anticoagulatory drugs. 63% of patients with OAC received non-vitamin-K antagonist oral anticoagulants (NOAC). A total of 168 patients were newly prescribed OAC after MitraClip, of whom 12 patients (7.1%) had no diagnosis of atrial fibrillation or venous thromboembolism. 40% of patients with OAC prior to MitraClip did not have any OAC after MitraClip. The adjusted risk of all-cause mortality was significantly increased in patients with no anticoagulatory treatment (HR 3.84, 95% CI 2.33–6.33, p < 0.0001) when compared to antiplatelet monotherapy whereas the other regimes were not significantly different.

Conclusions

This large real-world data analysis demonstrates a heterogeneous spectrum of prescriptions for anticoagulant therapies after MitraClip. Considering relevant differences in clinical outcome across treatment groups, major effort is warranted for controlled trials in order to establish evidence-based recommendations on anticoagulatory treatment after percutaneous mitral valve repair.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-022-01988-2.

Three-dimensional echocardiography for predicting mitral stenosis after MitraClip for functional mitral regurgitation

BACKGROUND

Postprocedural mitral stenosis (MS), or increased transmitral mean pressure gradient (TMPG), is one of the limitations of transcatheter edge-to-edge mitral valve repair using MitraClip (Abbott Vascular Inc., Santa Clara, USA); however, the usefulness of three-dimensional transesophageal echocardiography (3D-TEE) for predicting postprocedural MS in functional mitral regurgitation (MR) has not been fully elucidated.

METHODS

Eighty-two consecutive functional MR patients who underwent transcatheter mitral valve repair using MitraClip were retrospectively studied. Postprocedural MS was defined as TMPG ≥ 5 mmHg by echocardiography.

RESULTS

Ten patients had postprocedural MS, and 3D-TEE showed that patients with postprocedural MS had smaller preprocedural mitral valve orifice area (MVOA), anteroposterior and mediolateral diameter, leaflet area, and annulus area. Receiver operating characteristic analysis showed that leaflet area (area under the curve (AUC) 0.829), annulus area (AUC 0.813), anteroposterior diameter (AUC 0.797) and mediolateral diameter (AUC 0.803) evaluated using 3D-TEE were predictors of postprocedural MS, and their predictive abilities were higher than those of preprocedural MVOA (AUC 0.756) and preprocedural TMPG (AUC 0.716). Adding leaflet area to TMPG and MVOA resulted in higher C-statistics for predicting postprocedural MS (from 0.716 to 0.845 and from 0.756 to 0.853, respectively).

CONCLUSIONS

In functional MR patients treated with MitraClip, leaflet area and annulus area evaluated using 3D-TEE had high predictive values for postprocedural MS, and their predictive abilities were higher than those of preprocedural TMPG or MVOA.

Mitral Valve Atlas for Artificial Intelligence Predictions of MitraClip Intervention Outcomes

Severe mitral regurgitation (MR) is a cardiac disease that can lead to fatal consequences. MitraClip (MC) intervention is a percutaneous procedure whereby the mitral valve (MV) leaflets are connected along the edge using MCs. The outcomes of the MC intervention are not known in advance, i.e., the outcomes are quite variable. Artificial intelligence (AI) can be used to guide the cardiologist in selecting optimal MC scenarios. In this study, we describe an atlas of shapes as well as different scenarios for MC implantation for such an AI analysis. We generated the MV geometrical data from three different sources. First, the patients' 3-dimensional echo images were used. The pixel data from six key points were obtained from three views of the echo images. Using PyGem, an open-source morphing library in Python, these coordinates were used to create the geometry by morphing a template geometry. Second, the dimensions of the MV, from the literature were used to create data. Third, we used machine learning methods, principal component analysis, and generative adversarial networks to generate more shapes. We used the finite element (FE) software ABAQUS to simulate smoothed particle hydrodynamics in different scenarios for MC intervention. The MR and stresses in the leaflets were post-processed. Our physics-based FE models simulated the outcomes of MC intervention for different scenarios. The MR and stresses in the leaflets were computed by the FE models for a single clip at different locations as well as two and three clips. Results from FE simulations showed that the location and number of MCs affect subsequent residual MR, and that leaflet stresses do not follow a simple pattern. Furthermore, FE models need several hours to provide the results, and they are not applicable for clinical usage where the predicted outcomes of MC therapy are needed in real-time. In this study, we generated the required dataset for the AI models which can provide the results in a matter of seconds.

Immediate Post-Procedural and Discharge Assessment of Mitral Valve Function Following Transcatheter Edge-to-Edge Mitral Valve Repair: Correlation and Association with Outcomes

The correlation between residual mitral regurgitation (rMR) grade or mitral valve pressure gradient (MVPG), at transcatheter edge-to-edge mitral valve repair (TEEMr) completion and at discharge, is unknown. Furthermore, there is disagreement regarding rMR grade or MVPG from which prognosis diverts. We retrospectively studied 82 patients that underwent TEEMr. We tested the correlation between rMR or MVPG and evaluated their association, with outcomes. Moderate or less rMR (rMR ≤ 2) at TEEMr completion was associated with improved survival, whereas mild or less rMR (rMR ≤ 1) was not. Patients with rMR ≤ 1 at discharge demonstrated a longer time of survival, of first heart failure hospitalization and of both. The correlation for both rMR grade (r = 0.5, p < 0.001) and MVPG (r = 0.51, p < 0.001), between TEEMr completion and discharge, was moderate. MR ≤ 2 at TMEER completion was the strongest predictor for survival (HR 0.08, p < 0.001) whereas rMR ≤ 1 at discharge was independently associated with a lower risk of the combined endpoint (HR 4.17, p = 0.012). MVPG was not associated with adverse events. We conclude that the assessments for rMR grade and MVPG, at the completion of TEEMr and at discharge, should be distinctly reported. Improved outcome is expected with rMR ≤ 2 at TEEMr completion and rMR ≤ 1 at discharge. Higher MVPG is not associated with unfavorable outcomes.

Echocardiographic Variables Associated with Transvalvular Gradient After a Transcatheter Edge-To-Edge Mitral Valve Repair

BACKGROUND

Transcatheter edge-to-edge mitral valve repair may lead to a reduction in mitral valve area (MVA) and elevated mean transmitral gradient (TMG). The objectives of this study were to assess the value of baseline MVA by different imaging methods and to explore the associations between MVA indexed to body surface area or left ventricular forward stroke volume and postprocedural TMG.

METHODS

Preprocedural echocardiographic images from 76 consecutive patients were retrospectively reviewed. MVA planimetry from two-dimensional (2D) transthoracic echocardiography (MVA_TTE), 2D transesophageal echocardiography in the transgastric view (MVA_{2D TEE}), and three-dimensional (3D) transesophageal echocardiography (MVA_3D) were measured. Postprocedural TMGs were assessed at 1 to 3 months and all-cause mortality at 1 year.

RESULTS

Postprocedural mean TMG > 5 mm Hg was associated with a 3.42-fold (95% confidence interval [CI], 1.08-10.87; P = .04) increased risk for 1-year all-cause mortality. Patients with postprocedural TMG > 5 mm Hg (25% [19 of 76]) had significantly smaller preprocedural MVA_3D (3.9 ± 0.8 vs 5.2 ± 1.3 cm², P < .01) and MVA_TTE (4.9 ± 1.1 vs 5.8 ± 1.5 cm², P = .01) compared with patients without elevated TMG. No significant difference was found for MVA_{2D TEE} (P = .20). The best threshold values for MVA_3D and MVA_TTE to be associated with postprocedural TMG > 5 mm Hg were, respectively, 3.9 cm² (area under the curve [AUC] = 0.80; 95% CI, 0.66-0.94; sensitivity 62%, specificity 87%) and 4.6 cm² (AUC = 0.68; 95% CI, 0.54-0.82; sensitivity 53%, specificity 80%). MVA_3D indexed to body surface area and to stroke volume showed overall the best associations with postprocedural mean TMG > 5 mm Hg, with optimal thresholds, respectively, of 2.5 cm²/m² (AUC = 0.88; 95% CI, 0.77-0.98; sensitivity 92%, specificity 74%) and 95 cm²/L (AUC = 0.87; 95% CI, 0.77-0.97; sensitivity 85%, specificity 82%).

CONCLUSIONS

Elevated TMG following transcatheter edge-to-edge mitral valve repair was associated with increased mortality. The present results indicate that MVA_3D, MVA_3D indexed to body surface area, and MVA_3D indexed to stroke volume may be considered potential predictors of postprocedural TMG > 5 mm Hg and could help optimize patient selection, while the use of 2D methods for valve area were poorly associated with TMG.

Usefulness of Computed Tomography to Predict Mitral Stenosis After Transcatheter Mitral Valve Edge-to-Edge Repair

Multidetector computed tomography (MDCT) can provide valuable information for preprocedural planning of transcatheter mitral valve interventions. However, no data exists on pre-MDCT parameters predicting high transmitral pressure gradient (TMPG) post-MitraClip procedure. We analyzed the preprocedural MDCTs of 156 consecutive patients with mitral regurgitation undergoing MitraClip implantation at our institution. The mean TMPG was assessed by periprocedural transesophageal and pre-discharge transthoracic echocardiography. MDCT-derived mitral annulus area (MAA), anterior-posterior (AP) and medial-lateral (ML) mitral annulus diameters, and mitral valve orifice area (MVOA) were smaller in patients with mean TMPG ≥5 mmHg than those with mean TMPG <5 mmHg after 1-or 2-clip implantation. Small MAA, AP and ML diameters, and MVOA were moderately correlated with high TMPG post-MitraClip, in which MAA and MVOA had the highest degree of correlation after 1-clip (r = -0.46 both), whereas MAA and ML had the strongest degree of correlation after 2-clip (r = -0.39 both) and at discharge (r = -0.38 both). From the receiver-operating-characteristic curve analyses, no significant differences in the area under the curve were observed among these MDCT parameters for low TMPG after MitraClip implantation, except for those between MAA and AP diameter at discharge (p=0.026). For optimal cutoff values, MAA ≥1100 and ≥1300 mm² had positive predictive values of 89% and 91%, while both MAA ≥750 and ≥900 mm² had negative predictive values of 100%, for mean TMPG <5 mmHg after 1-and 2-clip implantation, respectively. In conclusion, in patients undergoing the MitraClip procedure, preprocedural MDCT parameters are useful to predict postprocedural mitral stenosis.